1. Field
The following description relates to a technique for processing an acoustic signal in a mobile device.
2. Description of Related Art
Due to a variety of user interface (UI) technologies used in a mobile devices and an improvement in a performance of mobile devices, users may desire to control the mobile device using a more convenient and natural UI. For example, a touch technique in place of an existing key pad may simultaneously provide entertainment and convenience to the users.
However, the touch technique may have several drawbacks. For example, a user needs to directly touch a touch screen of the mobile device to enable the touch to be recognized as an input. Other drawbacks may include, for example, the mobile device being deformed due to being frequently touched, or damage to the touch screen may be caused by a forcible input. Also, the mobile device may need to be miniaturized, and thus, the size of the touch screen may be limited. Also, the user may need to hold/look at the mobile device carefully for an extended period of time to perform an input operation. Thus, the user may become physically stressed or fatigued after using the mobile device for a long period of time.
To address some of the above-mentioned drawbacks, the mobile device may provide a UI of a new scheme to a user using a UI technology employing an acoustic sensor.
FIG. 1 illustrates conventional examples of acoustic-based interfaces.
Referring to FIG. 1, an Acoustic Pulse Recognition (APR) technique 110 may include an acoustic sensor attached to the surface of a device. A unique sound generated by a touch on a specific portion of a surface may be stored. The sound generated when a user touches the specific portion and previously stored sounds may be compared with each other, to determining a position where the touch operation is performed.
However, in the APR technique 110, it may be impossible to recognize a complex touch performed using a character or a figure, and only a position where the touch operation is performed may be determined. Also, when a number of the acoustic sensors is relatively low, the number of touched positions capable of being determined may be small. Also, a range in which the touch operation may be sensed is limited to only a surface of a corresponding device.
Alternatively, a Surface Acoustic Wave (SAW) technique 120 may be performed such that an interrupted position may be calculated. The SAW technique may determine a touch position when an advancing path of a sound wave is interrupted by objects such as fingers, a touch pen, and the like. The SAW technique may include a transmitter for emitting the sound wave to a surface of a corresponding device, a reflector for reflecting the sound wave at predetermined intervals, and a receiver attached on the surface.
However, this SAW technique 120 may also have problems in that the complex touch performed using the character or the figure may be impossible to be recognized, and only a touched position may be determined. Also, a range in which the touch operation may be sensed is limited to only a surface of a corresponding device.